Roll over vehicle washing apparatus with high and low pressure spray systems

ABSTRACT

A roll-over high-pressure washer for non-contact washing of stationary vehicles. A gantry frame having two independent U-shaped spray arms is mounted to roll back and forth over the vehicle, while independent low- and high-pressure spray systems mounted on each of the U-shaped spray arms pre-soak, wash and rinse the vehicle in a preprogrammed sequence. The U-shaped spray arms are maintained in close proximity to the upper surfaces of the vehicle, without contacting them, by primary non-vehicle-contacting and secondary vehicle-contacting sensing means. Side spray arms are also mounted on the gantry frame to wash the side surfaces of the vehicle.

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to non-contact vehicle washers;i.e.; a vehicle washer having no brushes or cloth strips to physicallyengage the vehicle. The invention relates more particularly to atwo-arm, high-pressure roll-over washer.

BACKGROUND OF THE INVENTION

Vehicle washers typically employ rotating brushes or depending clothstrips to clean the vehicle by direct physical contact; see for exampleU.S. Pat. Nos. 3,812,550, 4,118,820 and 4,470,167, all assigned toBivens Winchester Corporation of Danville, Va. The brushes typicallyconsist of long plastic strands or bristles which are extended radiallyoutwardly by centrifugal force as the brush rotates. Such vehiclewashers have been and still are very popular throughout the UnitedStates and in many foreign countries.

It is also well known to wash vehicles by non-contacting apparatus;i.e., apparatus which removes surface dirt by directing a stream ofhigh-pressure fluid at the vehicle. Both robotic devices and hand-heldwands have been used for this purpose.

Although many people prefer the non-contacting concept of high-pressurewashers, they have found that prior art commercial and home systems havenot produced entirely satisfactory results; i.e., pressure systems havesimply not proven as effective as brush systems in removing dirt.

On the other hand, pressure washers have advantages over brush systems.Because they do not have direct contact with the vehicle, spray systemscannot mar the vehicle's surface or damage surface projections such asmirrors and antennae. Also, the spray conforms itself to the contours ofa vehicle and can penetrate narrow crevices effectively.

SUMMARY OF THE INVENTION

The present invention provides a high-pressure washer which retains theinherent advantages of non-contacting systems, but which substantiallyimproves on washing performance and provides this performance in a formwhich is especially adapted for high-volume, commercial operations andwhich requires very little space, as compared to a conventional tunnelwasher.

In general, this is accomplished in a roll-over type washer including agantry frame mounted on tracks to move fore-and-aft over a parkedvehicle, and a pair of arms pivotally mounted to the gantry frame nearthe top and extending outwardly therefrom in opposite directions. Thearms carry nozzles for spraying the vehicle and are programmed to moveup and down, through respective arcs, relative to the vehicle, as thegantry moves fore-and-aft, thereby to maintain close proximity to thevehicle surfaces for maximum effectiveness and to provide full coverageof the vehicle over the top, along the hood and trunk and down to thebumpers and below.

In a preferred embodiment hereinafter described, a number of furtherfeatures are provided. The side surfaces of the vehicle are washed byessentially depending side arms carrying spray nozzles, one of the sidearms being fixed in position to the gantry frame and the other beingmovable in and out transversely of the frame to accommodate vehicles ofdifferent width.

According to another feature of the invention, each of the spray armscarries two independent spray systems, one for low-pressure operationand one for high-pressure operation. The low pressure system is used forpre-soak while the high-pressure system is used for washing and rinsing.Each system has its own nozzles and spray rates which are appropriate toits operation.

According to another feature of the invention, the pivoted horizontalarms are counterweighted and pneumatically position-controlled, withfail-safe return to a full up position. The cylinders of the pneumaticsystem (which can alternatively be oil or other fluid) are controlled byan electric eye system which looks across the vehicle and which isbacked up by a contact wheel. Accordingly, the arms are accuratelypositioned for close and effective spray proximity while, at the sametime, providing safety in operation for vehicle damage guidance.

BRIEF SUMMARY OF THE DRAWINGS

FIG. 1 is a perspective view of a roll-over washer according to thepresent invention relative to a stationary vehicle;

FIG. 2 illustrates in block diagram the movement program for the gantryframe of FIG. 1;

FIG. 3 illustrates the transversely movable spray arm;

FIG. 4 illustrates a single upper spray arm;

FIG. 5 shows the details of a representative portion of a spray system;and

FIG. 6 comprises five side views of the embodiment of FIGS. 1-5 indifferent stages of washing a vehicle.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a roll-over washer 10 to include an inverted U-shapedgantry frame 12 mounted for fore and aft movement on spaced parallelsteel rails 14 and 16 over a stationary vehicle 18. Front and rearU-shaped spray arms 20 and 24 are pivotally mounted to the gantry frame12 near the top center and carry spray tubes 21 having a plurality ofspray nozzles 22 to presoak, wash and rinse the front, upper, and rearsurfaces of the vehicle 18 according to a sequence of operation to belater described.

The U-shaped spray arms 20,24 are connected to the top center of gantryframe 12 to pivot about axes running transverse to the direction ofmovement of gantry frame 12. Each U-shaped spray arm is pivotalindependently of the other between an up position in which it lies in aplane substantially parallel to the ground away from vehicle 18, and adown position in which it is nearly perpendicular to the ground and inclose proximity to the end surface of vehicle 18. Suitable programmabledrive means (not shown) mounted on or in gantry frame 12 are operable toindependently adjust the U-shaped spray arms 20 and 24 throughrespective arcs between said up and down positions.

To wash the side surfaces of vehicle 18 a pair of substantially verticalside spray arms 26 and 28 are mounted on gantry frame 12, one side sprayarm mounted on each vertical support portion of gantry frame 12 adjacentthe vehicle 18. Side spray arms 26 and 28 are provided with spray tubes29 having side spray nozzles 30 facing the sides of vehicle 18 in asubstantially perpendicular manner. Side spray arms 26 and 28 andnozzles 30 operate with the U-shaped spray arms 20 and 24 and nozzles 22to pre-soak, wash and rinse the vehicle 18.

To provide for thorough cleaning of both sides of vehicles havingdifferent widths, i.e., to maintain the nozzles 30 of each side sprayarm 26 and 28 equidistant from their respective sides of vehicle 18,first side spray arm 26 is fixed relative to gantry frame 12 whilesecond side spray arm 28 is mounted to the other side of gantry frame 12to be transversely movable relative to the fore and aft travel of gantryframe 12 toward and away from vehicle 18. The vehicle 18 is positionedby a tire guide 34 and treadle 35, mounted in the floor and spaced apredetermined distance from and parallel to rail 14, such that the sideof vehicle 18 adjacent fixed side spray arm 26 is located at asubstantial constant distance from side spray arm 26, regardless of thewidth of the vehicle. After vehicle 18 has been driven into tire guide34 and parked on treadle 35 with one side at a set distance from sidespray arm 26, transversely movable side spray arm 28 is moved intoposition adjacent the opposite side of vehicle 18 at a distance equal tothat between fixed side spray arm 26 and the first side of the vehicle.The transverse adjustment and positioning of movable side spray arm 28is effected by suitable drive and sensor means to be hereinafterdescribed in greater detail.

The gantry frame 12, mounted for fore and aft movement on rails 14 and16, is initially positioned relative to vehicle 18 by programmable drivemeans (not shown) mounted on or in gantry frame 12. The limits of foreand aft movement of gantry frame 12 on the rails 14 and 16 are definedby limit switches 36, one mounted near each end of each rail. Contactwith limit switches 36 causes gantry frame 12 to either stop or reversedirection, depending on the programmed sequence of operations.

U-shaped spray arms 20 and 24 are provided with bothnon-vehicle-contacting and vehicle-contacting sensor means to preventcontact between the spray arms 20 and 24 or nozzles 22 and vehicle 18.The non-vehicle-contacting means comprises in the illustrativeembodiment a plurality of infrared beam emitters 38 with matchingreceivers 40, mounted near the lower corners of U-shaped spray arms 20and 24 essentially in the plane of movement of the side portion of eachU-shaped spray arm. A sensor beam 42 is generated between each emitter38 and receiver 40, the beam 42 transverse to the fore and aft motion ofgantry frame 12.

The vehicle-contacting sensor means comprises a sensor wheel 44 mountedon the nozzle carrying portion of each U-shaped spray arm 20,24 andconnected to a limit switch 46 which senses pressure in two directions.Wheel 44 is merely a back-up device, as it is generally preferred toavoid all contact with the vehicle surface. Accordingly, wheel 44 ismounted radially inwardly of sensor beams 42 such that it only contactsvehicle 18 in case of failure of the sensor beams to properly positionthe U-shaped spray arms 20 and 24.

Referring now to FIG. 2, the sequential operation of roll-over washer 10is shown in an arrow diagram. Gantry frame 12 begins in a home positionapproximately half way between the ends of rails 14 and 16, with theU-shaped spray arms in their up positions away from the vehicle. Whenthe vehicle is parked, gantry frame 12 travels rearwardly as shown inarrow A to the limit switches adjacent the rear of the vehicle, and theU-shaped upper spray arms and movable side spray arm are moved intoproper position with respect to the vehicle. In the pre-soak phase,denoted by arrows B and C, gantry frame 12 travels forwardly over thevehicle to the forward limit switches, and then reverses itself andtravels back to the rear limit switches, spraying the vehicle with aheated, low-pressure pre-soak solution to emulsify dirt and grime on thevehicle surface. At the end of the pre-soak phase, gantry frame 12reverses and travels forwardly again in the high-pressure wash phaserepresented by arrow D, in which the emulsified dirt is washed off thevehicle by a high-pressure soap spray. The gantry frame only traversesthe length of the vehicle once in the high-pressure was phase, reversingitself again at the forward limit switches and entering thehigh-pressure rinse phase represented by arrows D and E. The gantryframe travels all the way to the rear of the vehicle and then back tothe home position, rinsing soap from the vehicle with a high-pressureclear water spray. When the rinse phase is finished, all spray arms arereturned to their starting positions away from the vehicle, and theclean vehicle drives away.

Referring now to FIG. 3, the side spray arm system is illustrated ingreater detail, particularly movable side spray arm 28. Movable sidespray arm 28 moves via track follower 52 on guide rail 50 near the upperend of arm 28. The back and forth movement of spray arm 28 is effectedby a pair of hydraulic cylinders 54, which push and pull spray arm 28toward and away from the side of the vehicle (not shown) over whichgantry frame 12 is traveling.

Non-vehicle-contacting sensor means comprising an infrared emitter 56and receiver 58 are mounted on movable side spray arm 28 spacedvertically apart a distance at least equal to the height of arm 28.Emitter 56 and receiver 58 are mounted forward of both the nozzles 30and the arm 28 such that a sensor beam 60 generated between emitter 56and receiver 58 precedes the arm 28, spray tube 29 and nozzles 30 by adistance substantially equal to the distance between fixed spray arm 26and the opposite side of the vehicle. The side spray arm 28 movesdownward the vehicle to wash its side surface, and when the sensor beam60 is broken by contact with the vehicle, a signal is sent to amicroprocessor (not shown), which in turn shuts off or reverseshydraulic cylinders 54. In this manner the movable side spray arm 28 ismaintained at a relatively constant predetermined distance from the sideof the vehicle, and contact between the arm 28 or nozzles 30 and thevehicle is prevented.

Vehicle-contacting sensor means comprising spring-mounted sensor wheels62 and limit switches 64 provide a back-up to the sensor beam 60,preventing contact between the arm 28 or nozzles 30 and the side of thevehicle in case of failure of sensor beam 60. Wheels 62 project beyondnozzles 30, but not as far as sensor beam 60, and are spring-biased outof contact with limit switches 64. If a wheel 62 contacts a vehiclesurface, it is pressed into limit switch 64, sending a signal to themicroprocessor to reverse hydraulic cylinders 64.

Referring now to FIG. 4, one of the U-shaped spray arms is illustratedin greater detail. Since the U-shaped spray arms 20 and 24 areidentical, a detailed description of one is deemed sufficient forpurposes of clarity.

One of the U-shaped spray arms 20 is shown pivotally mounted to gantryframe 12 at mounting sites 32. Counterweights 66 are attached to theends of arm 20 near sites 32, biasing the spray arm to its upperposition away from the vehicle (not shown), while rubber bumpers 67limit the upward motion of spray arm 20. The drive means for theU-shaped spray arm 20 is a hydraulic cylinder 68, disposed betweengantry frame 12 and spray arm 20 to vertically displace the arm betweenits up position away from the vehicle and its down position adjacent thevehicle. Although the spray arm 20 is counterweighted to be biasedupward in the event of shut-off or failure of hydraulic cylinder 68,during normal operation the cylinder issued to both raise and lower arm20.

Hydraulic cylinders 68 are controlled by a microprocessor (not shown) tooperate U-shaped spray arms 20 and 24 in a preprogrammed sequence. TheU-shaped arms are programmed to go up and down, as the gantry frame 12travels back and forth, in a seesaw manner such that nozzles 22generally follow the contour of a vehicle. From a down position in whichthe nozzles 22 are adjacent one end of the vehicle, the arm travelsupwardly in an arc as gantry frame 12 rolls toward the opposite end ofthe vehicle. As the gantry frame 12 reaches its limit of travel, the armcompletes its arc in a raised position with the nozzles 22 adjacent theroof of the vehicle at a point approximately midway along the length ofthe vehicle. When gantry frame 12 reverses itself, the U-shaped sprayarm travels back down through the same arc to its original down positionadjacent the end of the vehicle.

The sequence of the U-shaped spray arms can be programmed to virtuallyany desired pattern to follow the general contour of various types ofvehicles. However, since wide variations in size and shape occur amongeven similar types of vehicles, the U-shaped spray arms of theillustrated roll-over washer 10 are provided with bothnon-vehicle-contacting and vehicle-contacting sensors to prevent contactbetween the U-shaped spray arms 20 and 24 and the vehicle.

The non-vehicle-contacting means comprise a plurality of infrared beamemitters 38 and matching receivers 40 mounted on projecting posts 39,which in turn are mounted on each U-shaped spray arm near the lowercorners thereof. In one corner two emitters 38 are mounted at rightangles to each other. In the other corner, directly opposite emitters38, two receivers 40 are mounted such that sensor beams 42 generatedbetween emitter beams 38 and receivers 40 are essentially parallel tothe transverse nozzle-carrying portion of the U-shaped spray arm.

The sensor beams 42 effectively precede the transverse nozzle-carryingportion of each U-shaped spray arm relative to the vehicle, and whenbroken by a rise or projection on the vehicle surface signal themicroprocessor to increase the rate of rise or upward motion of theU-shaped spray arm. The microprocessor then operates hydraulic cylinders68 to pull the U-shaped spray arm up out of the path of the obstructionuntil the sensor beam 42 is restored, preventing contact between thespray arm and the vehicle. In this manner the sensor beam system acts tofine tune or adjust the preprogrammed sequence of operation of theU-shaped spray arms guiding the spray arms over the vehicle surface inclose proximity thereto while preventing contact therebetween.

The use of the two sets of emitters 38 and receivers 40 on each U-shapedspray arm, spaced at 90° to each other in the plane of motion of thespray arm, ensures effective coverage regardless of the position of thespray arm relative to the vehicle.

The vehicle-contacting sensor wheels 44 and their accompanyingbi-directional limit switches 46, spring-mounted on the nozzle carryingportion of each U-shaped spray arm, are merely back-ups to the sensorbeams 42, as it is preferred to avoid all contact with the vehiclesurface. Accordingly, the wheels 44 are mounted radially inwardly ofsensor beams 42 such that they only contact vehicle 18 in case offailure of the sensor's beams 42 to properly position the U-shaped sprayarm. The limit switch 46 is responsive both in compression, for examplewhen the wheel bumps into the windshield of a vehicle, and in tensionfor example when the wheel catches on a bumper or other projection ofthe vehicle, to move the U-shaped spray arm or stop the gantry frame toprevent damage to the vehicle.

Referring now to FIG. 5, the spray system of each spray arm comprisinglow and high-pressure systems is illustrated in detail. Essentially thesame system is used in both the U-shaped spray arms 20 and 24, in thefixed side spray arm 26, and in the transversely movable side spray arm28. For simplicity of explanation, only the spray arm of transverselymovable side arm 28 will be described.

The low-pressure system generally denoted at 69 comprises a waterreservoir 70, a pressure regulator 72, a chemical/soap tank 74, spraytube 29, and low-pressure nozzle 30 all connected in series. Thislow-pressure system is operated by a microprocessor (not shown) to emita spray of approximately 40 psi pre-soak solution, via nozzles, 30, ontoa vehicle surface during steps A and B of the pre-soak phase (see FIG.2). The capacity of nozzles 30 is approximately 2.5 gallons per minute.Water is received from local water lines 76 and stored in reservoir 70until needed, :whereupon it is brought to the correct pressure byregulator 72, mixed with the pre-soak chemical or soap in tank 74, anddelivered to spray tube 29 and nozzles 30.

The high pressure system is generally denoted at 78 and comprises ahigh-pressure pump and reservoir combination 80, pressure regulator 82,a wash line 83 running from regulator 82 through a soap mixing tank 84to spray tube 21 and nozzles 30A, and a separate rinse line 86 runningfrom regulator 82 straight to spray tube 21 and nozzle 30A. In the highpressure wash phase (Step C in FIG. 2), water from local water line 76has previously been pumped up to pressure and stored in reservoir 80. Itis first delivered through regulator 82 and wash line 83 to soap mixingtank 82 to form a soap solution, and from there to spray tube 21 andnozzles 30A, from which it is emitted as a high-pressure (approximately750 psi) spray. In the rinse phase (Steps D and E in FIG. 2) the processis the same, except that the water from regulator 82 bypasses soapmixing tank 84 via rinse line 86 so that clear rinse water is emittedfrom nozzles 30A. High-pressure nozzles 30A in this preferred embodimentoperate at a capacity of approximately 70 gallons per minute.

Detailed Operation

Referring now to FIGS. 1-6, a vehicle 18 to be washed is drivenunderneath gantry frame 12 with the wheels of one side of the vehicle,in this embodiment the left side, in tire guide 34. At this point gantryframe 12 is in a home position with all of its spray arms retracted totheir respective up positions furthest from the vehicle 18 as shown inFIG. 6a. When the front vehicle wheel and tire guide 34 contacts treadle35, the driver is signaled to park the vehicle. This signal may be givenby an attendant supervising the operation of the roll-over washer, or itmay be an electrical or mechanical audio or visual signal for anautomatic or unattended roll-over washer.

With gantry frame 12 resting in a home position mediate front and rearlimit switches 36, and the vehicle parked with the plane of the gantryframe 12 extending approximately through its midpoint, the operatingsequence of the roll-over washer 10 can begin. As the gantry frame 12begins to travel rearwardly with respect to the vehicle along tracks 14and 16, rear U-shaped spray arm 24 is lowered by hydraulic cylinder 68,reaching its fully down position adjacent the rear bumper of the vehiclewhen the gantry frame reaches rear limit switches 36. This is shown inFIG. 6b. If the size and shape of the vehicle do not permit rearU-shaped spray arm 24 to be completely lowered, sensor beams 42 contactthe vehicle, reversing hydraulic cylinder 68 until sensor beams 42 arerestored. This prevents contact between the spray arm 24 and the vehicle18 and maintains the spray arm in close proximity to the surface of thevehicle. During the rearward travel of gantry frame 12, front U-shapedspray arm 20 is maintained in its raised position away from the vehicle18. Movable side spray arm 28 is moved toward the right side of thevehicle by hydraulic cylinders 54 as gantry frame 12 travels rearwardly,with sensor beam 60 maintaining movable side spray arm 28 a distancefrom the right side of the vehicle equal to the distance of fixed sidespray arm 26 from the left side.

When gantry frame 12 contacts rear limit switches 36, the pre-soak cyclebegins. The low-pressure spray systems 69 of all the spray arms areactivated to emit a heated pre-soak solution from U-shaped spray armnozzles 22 and side spray arm nozzles 30. At the same time, gantry frame12 reverses itself, traveling forward along the tracks 14 and 16 withrespect to the vehicle to the position shown in FIG. 6c. Front U-shapedspray arm 20 is lowered and rear U-shaped spray arm 24 is raised, eachin its respective pre-programmed arc, to generally follow the contour ofthe vehicle. Sensor beams 42 prevent contact of the U-shaped spray armswith the vehicle if its contour at any point falls outside the limits ofthe preprogrammed sequence. When gantry frame 12 reaches forward limitswitches 36, shown in FIG. 6d front U-shaped spray arm 20 is in itsfully down position adjacent the front bumper of the vehicle, and rearU-shaped spray arm 24 is in its fully raised position adjacent themidpoint of the vehicle. Movable side spray arm 28 is transverselyadjusted relative to the movement of the gantry frame 12 with respect tothe right side of the vehicle in the same manner.

After as many pre-soak passes as desired are completed, the roll-overwasher 10 goes through the wash and rinse phases in a mannersubstantially identical to that of the pre-soak phase, the onlydifference being that the high pressure spray system 78 operates inplace of the low-pressure spray systems 69. When the roll-over washer 10has completely finished pre-soaking washing and rinsing the vehicle 18,it returns to its home position mediate limit switches 36, the front andrear U-shaped spray arms 20 and 24 are retracted to their fully raisedpositions away from the vehicle 18, the movable side spray arm 28 isretracted away from the right side of the vehicle 18, and the cleanedvehicle is driven away. This condition is shown in FIG. 6e.

It is to be understood that the foregoing description of the illustratedembodiment is not intended to be limiting, and that variousmodifications of the illustrative embodiment lie within the scope of theinvention.

We claim:
 1. A brushless roll-over washing apparatus for washingstationary vehicles comprising:a gantry frame mounted on tracks to movefore and aft over said stationary vehicle; a pair of spray armspivotally mounted to the gantry frame near the top and extendingoutwardly therefrom in opposite directions; a spray system mounted oneach of said arms having nozzles for spraying a vehicle; drive means formoving said spray arms through respective arcs up and down relative tosaid stationary vehicle, as said gantry frame moves for and aft, in apredetermined sequence of operation in which said spray arms essentiallyfollow the contour of said vehicle.
 2. Apparatus as defined in claim 1,wherein said spray system comprises independent high-and low-pressurespray systems.
 3. Apparatus as defined in claim 2, wherein saidlow-pressure spray system is operable to emit low-pressure pre-soaksolution through said nozzles onto the vehicle.
 4. Apparatus as definedin claim 2, wherein said high-pressure spray system is operable to emitboth a high-pressure soak spray and a high-pressure clear water rinsespray through said nozzles onto the vehicle.
 5. Apparatus as defined inclaim 1, wherein said drive means comprises at least one hydrauliccylinder for each U-shaped spray arm.
 6. Apparatus as defined in claim1, wherein said predetermined sequence of operation comprises pre-soak,wash, and rinse phases.
 7. Apparatus as defined in claim 6, wherein saidpredetermined sequence of operations is controlled by a microprocessor.8. Apparatus as defined in claim 1, including means for limiting thefore and aft movement of said gantry frame.
 9. Apparatus as defined inclaim 8, wherein said means for limiting the fore and aft movement ofsaid gantry frame comprises at least one limit switch.
 10. A roll-overhigh-pressure washer for non-contact washing of stationary vehicles,comprising:a gantry frame mounted to move fore and aft over saidstationary vehicle; a pair of U-shaped spray arms pivotally mounted tothe gantry frame near the top and extending outwardly therefrom inopposite directions for washing the upper surfaces of said vehicle; apair of side spray arms mounted to move with said gantry frame forwashing the side surfaces of said vehicle; sensor means mounted on saidU-shaped spray arms to prevent contact between said U-shaped spray armsand said vehicle; each of said spray arms having mounted thereonindependent high- and low-pressure spray systems having nozzles forspraying said vehicle.
 11. Apparatus as defined in claim 10, whereinsaid sensor means comprises both primary sensor means and secondarysensor means.
 12. Apparatus as defined in claim 11, wherein said primarysensor means is non-vehicle-contacting.
 13. Apparatus as defined inclaim 11, wherein said secondary sensor means is vehicle-contacting. 14.Apparatus as defined in claim 10, wherein one of said side spray arms istransversely movable relative to the fore and aft movement of saidgantry frame toward and away from the side surface of said vehicle. 15.A brushless roll-over high-pressure washer for non-contact spray washingof stationary vehicles in a predetermined sequence of pre-soak, wash andrinse phases, comprising:an inverted U-shaped gantry frame mounted ontracks to move fore and aft over said stationary vehicle; a pair ofU-shaped upper spray arms pivotally mounted to the gantry frame near thetop and extending outwardly therefrom in opposite directions for washingthe upper surfaces of said vehicle; programmable drive means forindependently moving said U-shaped upper spray arms through respectivearcs up and down relative to said stationary vehicle, as said gantryframe moves fore and aft, to maintain said U-shaped spray arms in closeproximity to the upper surfaces of said vehicle; primary non-contactsensor means mounted on said U-shaped spray arms for preventing contactbetween said U-shaped upper spray arms and said vehicle as the gantryframe moves fore and aft; a fixed side spray arm mounted on said gantryframe for washing the surface of a first side of said vehicle; guidemeans for positioning said vehicle with respect to said gantry framesuch that said first side of said vehicle is at a predetermined distancefrom said fixed side spray arms; a movable side spray arm mounted onsaid gantry frame opposite said fixed side spray arm for washing thesurface of the second side of said vehicle, said movable side spray armadjustable toward and away from said second side of said vehicle tomaintain it therefrom at a distance substantially equal to said firstpredetermined distance; primary non-contact sensor means mounted on saidmovable side spray arm for preventing contact between said movablebeside spray arm and said vehicle; independent high- and low-pressurespray systems, having nozzles for spraying said vehicle, mounted on eachof said U-shaped upper spray arms and on said fixed and movable sidespray arms; secondary contact sensor means mounted on said U-shapedupper spray arms and said vehicle; counterweighting means mounted onsaid U-shaped upper spray arms to bias said U-shaped upper spray armsupward away from said vehicle.
 16. Apparatus as defined in claim 15,wherein said secondary contact sensor means is mounted inwardly of saidprimary non-contact sensor means relative to said vehicle.
 17. Apparatusas defined in claim 16, wherein said primary non-contact sensor meanscomprises a system of light beam emitters and receivers.
 18. Apparatusas defined in claim 17, wherein light beams generated between said beamemitters and receivers are substantially parallel to the transverseportion of said U-shaped spray arm.
 19. Apparatus as defined in claim16, wherein said secondary contact sensor means comprises aspring-mounted sensor wheel and limit switch.
 20. Apparatus as definedin claim 19, wherein said limit switch is bi-directional, responding toboth tension and compression of said spring-mounted sensor wheel. 21.Apparatus as defined in claim 15, wherein said programmable drive meanscomprises at least one hydraulic cylinder controlled by amicroprocessor.